Gameplay: Well I think it should be a lot like Uncharted 2. Pick up weapons instead of having loadouts fits the tone of the games a lot better than the COD-inspired crap we got in 3.

Maps: They should have Power Weapons spawn at 4 different areas of the map, that way people move around and avoid camping the same spot for a hammer. They should also be really cool and, oh yeah, be different in different areas of the map.

Power Plays: They suck get rid of them.

Loadouts: They suck get rid of them.

Kickbacks: Make them defensive, not offensive or just get rid of them cuz right now, they suck.

Late Join: It sucks get rid of it.

Playlists: Take a look at Uncharted 2's playlists and use them for 4.

Free 4 All: Keep it, and name it "Free '4' All".

Graphics: Make them better than the ones in Uncharted 2, because the ones in Uncharted 3 sucked. Those looked like N64 graphics.

Customization: Get rid of it because it's gotten freaking ridiculous and not in a good way.